From owner-svn-src-all@freebsd.org Thu Jan 26 01:24:06 2017 Return-Path: Delivered-To: svn-src-all@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id CE029CC1B9E; Thu, 26 Jan 2017 01:24:06 +0000 (UTC) (envelope-from cy@FreeBSD.org) Received: from repo.freebsd.org (repo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id A87C9A2F; Thu, 26 Jan 2017 01:24:06 +0000 (UTC) (envelope-from cy@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id v0Q1O5L8015104; Thu, 26 Jan 2017 01:24:05 GMT (envelope-from cy@FreeBSD.org) Received: (from cy@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id v0Q1O5Bc015101; Thu, 26 Jan 2017 01:24:05 GMT (envelope-from cy@FreeBSD.org) Message-Id: <201701260124.v0Q1O5Bc015101@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: cy set sender to cy@FreeBSD.org using -f From: Cy Schubert Date: Thu, 26 Jan 2017 01:24:05 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r312787 - in head: contrib/ipfilter/lib sys/contrib/ipfilter/netinet X-SVN-Group: head MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 26 Jan 2017 01:24:06 -0000 Author: cy Date: Thu Jan 26 01:24:05 2017 New Revision: 312787 URL: https://svnweb.freebsd.org/changeset/base/312787 Log: Currently the fragment info is placed at the top of the linked list under a shared read lock. This patch attempts to upgrade the lock to an exclusive write lock. If the exclusive write lock fails to be obtained, the current fragment is not placed at the head of the list. This portion of the patch was inspired by NetBSD ip_frag.c r1.4 (which effectively removed the section of code that performed the reordering). The patch to sys/contrib/ipfilter/netinet/ip_compat.h adds the MUTEX_TRY_UPGRADE macro to support the patch to ip_frag.c. The patch to contrib/ipfilter/lib/rwlock_emul.c supports this patch by emulating the mutex in userspace when exercised by ipftest(1). Inspired by: NetBSD ip_frag.c r1.4 MFC after: 1 month Modified: head/contrib/ipfilter/lib/rwlock_emul.c head/sys/contrib/ipfilter/netinet/ip_compat.h head/sys/contrib/ipfilter/netinet/ip_frag.c Modified: head/contrib/ipfilter/lib/rwlock_emul.c ============================================================================== --- head/contrib/ipfilter/lib/rwlock_emul.c Wed Jan 25 23:12:03 2017 (r312786) +++ head/contrib/ipfilter/lib/rwlock_emul.c Thu Jan 26 01:24:05 2017 (r312787) @@ -56,6 +56,27 @@ void eMrwlock_write_enter(rw, file, line } +void eMrwlock_try_upgrade(rw, file, line) + eMrwlock_t *rw; + char *file; + int line; +{ + if (rw->eMrw_magic != EMM_MAGIC) { + fprintf(stderr, "%s:eMrwlock_write_enter(%p): bad magic: %#x\n", + rw->eMrw_owner, rw, rw->eMrw_magic); + abort(); + } + if (rw->eMrw_read != 0 || rw->eMrw_write != 0) { + fprintf(stderr, + "%s:eMrwlock_try_upgrade(%p): already locked: %d/%d\n", + rw->eMrw_owner, rw, rw->eMrw_read, rw->eMrw_write); + abort(); + } + rw->eMrw_write++; + rw->eMrw_heldin = file; + rw->eMrw_heldat = line; +} + void eMrwlock_downgrade(rw, file, line) eMrwlock_t *rw; char *file; Modified: head/sys/contrib/ipfilter/netinet/ip_compat.h ============================================================================== --- head/sys/contrib/ipfilter/netinet/ip_compat.h Wed Jan 25 23:12:03 2017 (r312786) +++ head/sys/contrib/ipfilter/netinet/ip_compat.h Thu Jan 26 01:24:05 2017 (r312787) @@ -165,6 +165,7 @@ struct ether_addr { # define READ_ENTER(x) rw_rlock(&(x)->ipf_lk) # define WRITE_ENTER(x) rw_wlock(&(x)->ipf_lk) # define MUTEX_DOWNGRADE(x) rw_downgrade(&(x)->ipf_lk) +# define MUTEX_TRY_UPGRADE(x) rw_try_upgrade(&(x)->ipf_lk) # define RWLOCK_INIT(x,y) rw_init(&(x)->ipf_lk, (y)) # define RW_DESTROY(x) rw_destroy(&(x)->ipf_lk) # define RWLOCK_EXIT(x) do { \ @@ -421,6 +422,8 @@ extern void freembt __P((mb_t *)); # define MUTEX_DOWNGRADE(x) eMrwlock_downgrade(&(x)->ipf_emu, \ __FILE__, __LINE__) +# define MUTEX_TRY_UPGRADE(x) eMrwlock_try_upgrade(&(x)->ipf_emu, \ + __FILE__, __LINE__) # define READ_ENTER(x) eMrwlock_read_enter(&(x)->ipf_emu, \ __FILE__, __LINE__) # define RWLOCK_INIT(x, y) eMrwlock_init(&(x)->ipf_emu, y) @@ -671,6 +674,7 @@ extern char *ipf_getifname __P((struct i # define READ_ENTER(x) ; # define WRITE_ENTER(x) ; # define MUTEX_DOWNGRADE(x) ; +# define MUTEX_TRY_UPGRADE(x) ; # define RWLOCK_INIT(x, y) ; # define RWLOCK_EXIT(x) ; # define RW_DESTROY(x) ; Modified: head/sys/contrib/ipfilter/netinet/ip_frag.c ============================================================================== --- head/sys/contrib/ipfilter/netinet/ip_frag.c Wed Jan 25 23:12:03 2017 (r312786) +++ head/sys/contrib/ipfilter/netinet/ip_frag.c Thu Jan 26 01:24:05 2017 (r312787) @@ -745,7 +745,7 @@ ipf_frag_lookup(softc, softf, fin, table } else if (off == 0) f->ipfr_seen0 = 1; - if (f != table[idx]) { + if (f != table[idx] && MUTEX_TRY_UPGRADE(lock)) { ipfr_t **fp; /* @@ -763,6 +763,7 @@ ipf_frag_lookup(softc, softf, fin, table table[idx]->ipfr_hprev = &f->ipfr_hnext; f->ipfr_hprev = table + idx; table[idx] = f; + MUTEX_DOWNGRADE(lock); } /*